Medical devices useful for fixating soft tissue are known in the art. These devices include screws, bone pins, staples, sutures and suture anchors. Of particular interest in orthopedic reconstructive surgery are suture anchors. Suture anchors typically consist of a member having a suture mounted thereto. Surgical needles are usually mounted to the ends of the suture. A suture anchor is typically inserted into a bore hole drilled into a bone. The suture extends out from the bore hole and is used to attach soft tissue such as joint cartilage to the surface of the bone.
Several types of suture anchor devices are known in the art. One type of suture anchor is known as a "arced" anchor. This type of suture anchor is disclosed in U.S. Pat. Nos. 4,898,156, 5,207,679, 5,217,486, 5,417,712, 5,505,735, and 5,522,845 which are incorporated by reference. The arced anchor may have a cylindrical body member. Deformable arc members extend from the body member. Suture is typically mounted in a suture mounting hole in the anchor member or about the anchor member for example in an eyelet. The arc members are deformed backward during insertion by the hard outer cortex of the bone as the anchor is inserted into a bone bore hole. When in place in the bone bore hole, the arcs subsequently relax in the cancellous bone region, allowing the arcs to engage cancellous bone and thereby fixating the suture anchor in the bore hole. Another type of suture anchor is a threaded anchor. Many threaded anchors are self-tapping and do not require a pre-drilled bone bore hole, while other anchors require a drilled and tapped bore hole. The anchors have an elongated body with a distal point end and a plurality of thread flights. The threaded anchors may have an optional cutting flute. The threaded anchors typically have a proximal drive end that is engaged by a driving instrument to rotate the threaded anchor into position within the bone. A suture is typically mounted to the anchor, for example, in a hole contained in the anchor body or to an eyelet. Examples of screw threaded suture anchors are contained in U.S. Pat. Nos. 5,013,316, 5,411,506 and 5,411,523 which are incorporated by reference.
Another type of suture anchor that is known in this art is referred to as a "wedge" suture anchor. The wedge anchor typically has a triangular profile. A suture is typically mounted in a hole contained in the wedge anchor body. The wedge anchor is inserted into a bone bore hole and caused to partially rotate, thereby causing one or more edges to engage bone. Examples of wedge anchors are contained in U.S. Pat. No. 5,683,418, which is incorporated by reference. Other types of suture anchors are also known in the art including force-fit anchors having compressible anchor bodies, two-piece umbrella-type anchors that are expanded after placement in a bone bore hole, and temperature induced shape-memory anchors.
Most suture anchors utilize some type of a mounting hole in the anchor body to mount a suture. The mounting hole is typically transverse to the longitudinal axis of the anchor body. Typically the mounting hole is contained in the proximal section of the anchor, although it can be at the middle, or in a distal section.
Most suture anchors have a single strand of suture mounted to the anchor. For most soft tissue fixation surgical procedures, this is adequate to achieve the desired amount of soft tissue fixation to the bone surface. However, certain procedures require the use of more than one suture to obtain satisfactory soft tissue fixation. For example, multiple sutures are often needed in surgical procedures to repair the rotator cuff, in plastic surgery, in cosmetic procedures, and in surgical procedures involving repair of the knee, ankle, elbow, hand Achilles tendon, etc.
Presently, when more than one suture is necessary, typically, suture anchors are used having two or more strands of suture mounted in a single suture mounting hole. The opening in the anchor can be enlarged to accommodate multiple suture stands. However, there are problems associated with the use of such suture anchors in surgical procedures. The problems include suture binding, tangling, inadvertent knotting and twisting, all of which may interfere with the surgeon's ability to efficiently perform a surgical procedure.
Accordingly there is a need in this art for novel suture anchors that can be used with multiple suture anchors, which overcome these problems.